SDBGEN - Generating the System Databanks

The Mimer SQL system databanks SYSDB, TRANSDB, LOGDB and SQLDB are generated by the SDBGEN program.

SDBGEN will load the system tables, see Data Dictionary Tables, and defines the data dictionary views detailed in the Mimer SQL Reference Manual.

Note: A databank created for one SYSDB cannot be accessed by using a different SYSDB even if identical data dictionary definitions are created in it.

UNIX: A local database is set up on a Unix node by running the dbinstall command (see the dbinstall man-page) and SDBGEN is started automatically when required.

The databank files are by default created in the database home directory which is not the ideal arrangement from a security and performance point of view, see Re-creating TRANSDB, LOGDB and SQLDB for guidelines relating to placement and organization.

If there is more than one disk available on the system, it is recommended that directories be created on those disks specifically for locating databanks. When created, the LOCAL definition for the database should be updated in the/etc/sqlhosts file by changing the single home directory path to a directory path list that includes these directories. The list is colon separated as can be seen in the following example, where the database is called "hotel":

hotel /usr/db/hotel:/extra/db/hotel:/extra2/db/hotel

After this update is made, the database server can be stopped and the selected databank files can be moved from the database home directory to their new locations. When moved, the database server can be started again.

VMS: In order to create the Mimer SQL system databanks for a local database on an OpenVMS node, an entry for the database must be specified in the SQLHOSTS file. SDBGEN should then be executed to create the actual database. See Syntax for information on how to run SDBGEN.

Win: You set up a local database on a Windows node by running the Mimer Administrator. The Mimer Administrator invokes the SDBGEN program in order to create the system databanks when required.

The system databanks are distributed automatically, depending on the number of disks available. Windows help is provided with both the Mimer Administrator and SDBGEN to guide you through setting up a local database.

Setting the Initial Size

The initial size for each of the Mimer SQL system databanks can be specified.

The size for the databanks is specified in Mimer SQL pages. The size of a Mimer SQL page is 2 kilobytes.

Setting Password for System Administrator

The database administration ident SYSADM is also created and a password (passwords are case-sensitive) must be specified for this ident. It should be chosen carefully and changed at appropriate intervals the ALTER IDENT statement.

Caution: Care should be taken to safeguard the SYSADM password, because if it is lost it cannot be retrieved from the system and it is not possible to set a new one.

Syntax

UNIX: On Unix, the dbinstall utility is used to create the system databanks.

Win: On Windows, the Mimer Administrator is used to create the system databanks.

The SDBGEN command has two purposes. Either to create a new set of system databank files, or to upgrade database files created in an earlier version of Mimer SQL to the current version.

The SDBGEN program is controlled by flagged information specified on the command-line.

The syntax (expressed in VMS-style) for creating databank files is as follows: